2.2.1.2 - 2.2.1.2 crystallization in polymorphic forms, to 3.0 and 2.7 A resolution. Crystal form 1 belong to the orthorhombic space group C2221 with five monomers per asymmetric unit and crystal form 2 belong to the monoclinic space group P21 with ten monomers per asymmetric unit 2.2.1.2 crystallization with a combination of micro- and macro-seeding techniques, space group: P212121 2.2.1.2 hanging drop method, mother liquid consits of: 27% w/v polyethylenglycol 4000, 0.08% NaN3, 0.3 M ammonium acetate, pH 4.4 2.2.1.2 hanging-drop vapor diffusion method 2.2.1.2 in complex with arabinose 5-phosphate, hanging drop vapor diffusion method, using 0.2 M K/Na tartrate and 20% (w/v) PEG 3350 2.2.1.2 mutant enzyme E60Q/F132Y, hanging drop vapor diffusion method, using 200 mM ammonium acetate (pH 4.4), 10% (w/v) PEG 6000, and 25% (v/v) glycerol 2.2.1.2 mutant enzyme F178Y with bound D-tagatose 6-phosphate , hanging drop vapor diffusion method, using 0.15 M Li2SO4, 18% (w/v) PEG 3350. Mutant enzyme E96Q with bound D-fructose 6-phosphate, hanging drop vapor diffusion method, using 0.2 M DL-malic acid pH 7.0, 18% (w/v) PEG3350 2.2.1.2 structure of the unliganded F178Y mutant is determined to 1.4 A resolution